ENVIRONMENTAL SCIENCE 3205 CHAPTER 1 AN INTRODUCTION TO ENVIRONMENTAL SCIENCE

Transcription

1 ENVIRONMENTAL SCIENCE 3205 CHAPTER 1 AN INTRODUCTION TO ENVIRONMENTAL SCIENCE

2 Chapter 1: Ecology is the study of the interrelationships between organisms, and between those organisms and their environment. Environmental Science is a mix of sciences (ecology, chemistry, biology, math) and social studies (municipal, Provincial, and National government, law, art, and politics). A study of how humans relate to their environment and the impacts we have on it...both positive and negative. A study of the physical environment, and how its chemistry and life are impacted by us. A relatively new science, its grown out of ecology because of these paradigm shifts.

3 What are some natural resources, both RENEWABLE and NON-RENEWABLE, that are found on Earth? Define Renewable and Non-renewable resources

4 Let s pick one of these resources, the FISHERIES: How did people view the fisheries resource in the past? It was believed that fish was an UNLIMITED resource that could be EXPLOITED (i.e., take as much as you want).

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7 What HAPPENED historically to change the view? 1.Fish stocks depleted with overfishing 2.Advancements in Fishing Technology (ex: fishfinders, dragnets, big trawlers) 3.Scientific research led to greater understanding What FACTORS do people consider when managing the fisheries industry TODAY? Social Factors culture, politics, values, needs Economic Factors industry, jobs Environmental Factors nature, beauty

8 SUSTAINABILITY DIAGRAM

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10 SUSTAINABILITY It means living WITHIN the EARTH s LIMITS. It means meeting the needs of the PRESENT without compromising the ability of the FUTURE to meet their needs. Another name: SUSTAINABLE DEVELOPMENT How much Earth do you Need? P. 38 Ecological Footprint Assignment

11 What Are Some of the Effects of this New Paradigm? 1. We as a society act on a new Precautionary Principle...a moral, legal and political ideas which states : if an idea or policy might cause harm to the public or the environment, it is the responsibility of those pushing the idea or policy to prove that it will not cause harm, unless there s a lot of scientific evidence to suggest its ok. In other words, caution ahead of time, BEFORE we make decisions or take action. That s completely opposite of the old development ethic. It applies to individuals, businesses, and Governments.

12 2. We have created legislation to guide people, businesses, and Governments to be more environmentally sustainable. Ex. NL s Sustainable Development Act, hunting and fishing regulations, forestry planning requirements, industry clean up, limiting air pollution, protecting water, reducing carbon emissions.

13 3. We monitor human activity to ensure its sustainable. Being more aware of what you re doing will help make you more sustainable. (Ex. Any idea how much garbage your family puts out in a year? How much water your home uses? How much energy your family demands? How much earth is needed to support your lifestyle?)

14 4. We recognize now that our lifestyle choices have an ecological footprint. Earth s resources DO have limits, and can only provide a certain amount of resources with today s technology. It is an estimate of how much land and sea space is needed to supply humans with resources and deal with our wastes under current technology. (Page 34)

15 Scientific Method Is a planned organized approach to solving a problem Steps: 1. Define a problem 2. Make a hypothesis to suggest an explanation for your problem 3. Gather information/data (testing) 4. Record information attained and results are studied 5. Analyze data and make conclusions Text P. 5 & 6

16 Paradigm and Paradigm Shift PARADIGM The way humans view the world. PARADIGM SHIFT A rare and significant change in the way humans view the world (i.e., a change in our paradigm!).

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19 Paradigm Shifts... Examples: IDEA: SHAPE OF THE EARTH PAST: The Earth is FLAT. PRESENT: The Earth is ROUND. IDEA: ORBITING OF PLANETS PAST: The Sun revolves around the Earth. PRESENT: The EARTH revolves around the Sun. IDEA: SANTA CLAUS PAST (children): Santa Claus brings us presents! PRESENT (adults: There is no Santa Claus? What?

20 THE ECOLOGY PARADIGM SHIFT PAST: EXPLOITATION It was believed that resources were UNLIMITED and put on the Earth for the SOLE benefit of HUMANS. Humans can take as much as we want as often as we want. PRESENT: SUSTAINABILITY Earth s Resources are in LIMITED SUPPLY. Humans are CARETAKERS of the Earth and need to practice SUSTAINABILITY in our management of resources.

21 Environmental Attitudes/Ethics Developmentalist AKA Utilitarian. Humans are Masters of nature and that Earth and its resources. The resources are on Earth for our benefit. Take what you can at all expense. $$$ Conservationist Believes in using the Earths resources. Works towards a balance of resource use and resource availability. Sustainable use of resources. Preservationist Nature is special and should be left untouched. Preserve the natural beauty of an area, all living things at any cost to social or economic want or needs.

22 How Did Different Cultures Use Our Resources? Aboriginal cultures... - hunters and gatherers Harvest extraction - seasonally nomadic, effects spread out - harvest technology was not very efficient, harvests more sustainable - saw themselves as a part of the environment, not masters of it...strong cultural connections to the resources - as numbers of aboriginals go up, harvest impacts grow quickly, introduced technology lets them take more per capita than other people Europeans... Europeans... - brought a money based economy, and a more utilitarian view of unlimited resources...they were there to use - the wild environment was seen as something to be brought under control of people, for our own benefit - people were masters of the environment, and the most superior thing in it - community based, harvesting and producing in the area There is now an ongoing paradigm shift...more people realize that resources do have limits,

23 Ecosystem A community of organisms and the physical environment in which they live.

24 So What Makes an Ecosystem Stable? 1. Recycling of important nutrients like water, carbon, nitrogen (and others) between the living and nonliving parts of the environment.(because earth is a closed system remember!) 2. Healthy populations of organisms that do not increase or decrease dramatically.. 3. A wide variety of biodiversity that makes food webs stable if there is an environmental change 4. The ability to rebound from disturbances ( repair itself ) using succession. 5. Balanced ecological pyramids 6. Sustainable resource use. 7. No major disturbances

25 Habitat The place where an organism lives. Not the organisms home! It s habitat!

26 Abiotic Factors The NON-LIVING FACTORS which affect life in an ecosystem. Examples include:

27 Biotic Factors The LIVING factors in an environment. Biotic factors include both: the ORGANISMS AND the interactive RELATIONSHIPS BETWEEN organisms Examples include:

28 Symbiotic Relationship Relationships in which TWO ORGANISMS LIVE in CLOSE ASSOCIATION such that at LEAST ONE BENEFITS.

29 5 Types of Symbiotic Relationships 1. Mutualism 2. Commensalism 3. Parasitism 4. Parasitoidism 5. Predator-Prey

30 1. Mutualism BOTH organisms BENEFIT. Examples: Polyp and hermit crab Pollination Egyptian plover and crocodile

31 2. Commensalism ONE organism benefits, ONE organism is neither benefited nor harmed Examples: Beaver and fish Trees and nesting birds Clown fish/anemone

32 3. Parasitism One organism, the PARASITE, benefits. One organism, the HOST, is harmed. Examples: Tapeworm and human

33 4. Parasitoidism One organism benefits, one organism is killed a slow death Example: Parasitic wasp and other insects /animals/bugs-animals/bees-andwasps/wasp_attacks_spider.html

34 5. Predator-Prey One organism benefits, one organism is harmed/killed quickly Example: Lion and zebra Lynx and snowshoe hare WvdM

35 FEEDING RELATIONSHIPS in ECOSYSTEMS Trophic Structure Types of Organisms Producer Consumer Decomposer Food Chain VS. Food Web Pyramid of Energy Population VS. Community Ecotone Microecosystem

36 TROPHIC STRUCTURE Feeding relationships within an ecosystem Types of Feeders PRODUCER CONSUMER DECOMPOSER

37 PRODUCERS Also known as AUTOTROPHS ( selffeeders ) Organisms that CAN produce their own food and oxygen through PHOTOSYNTHESIS. Examples: Plants Algae

38 CONSUMERS: Also known as HETEROTROPHS ( otherfeeders ) Organisms that CANNOT produce their own food and feed on OTHER organisms to survive.

39 TYPES OF CONSUMERS: Types based on WHAT the organism eats HERBIVORE Eats plants Ex: CARNIVORE Eats other consumers Can be either a PREDATOR or a SCAVENGER (or both) Ex: OMNIVORE Eats plants AND animals Ex:

40 CATEGORIES OF CONSUMERS: Category based on where organism is LOCATED in food chain Categories: PRIMARY (1 0 ) Also known as FIRST ORDER consumers Feed on PRODUCERS Considered the SECOND trophic level. SECONDARY (2 0 ) Also known as SECOND ORDER consumers Feed on PRIMARY CONSUMERS Considered the THIRD trophic level. TERTIARY (3 0 ) Also known as THIRD ORDER consumers Feed on SECONDARY CONSUMERS Considered the FOURTH trophic level.

41 DECOMPOSERS: Also known as DETRITIVORES or SAPROBES Organisms that get their nutrients by breaking down DETRITUS Detritus is decaying plant and animal material

42 FEEDING RELATIONSHIP DIAGRAMS FOOD CHAIN FOOD WEB PYRAMID OF ENERGY

43 FOOD CHAIN A diagram that defines ONE SINGLE CHAIN of feeding relationships in an ecosystem Starts with PRODUCERS and connects with arrows up to the TOP CARNIVORES Ex: Hawk Downy Woodpecker Spruce budworm Black spruce tree

44 FOOD CHAIN... Why do food chains usually only go up as high as the third order, or tertiary consumer? Energy decreases as it is passed up the food chain, and the top levels have the least energy, so they are limited in levels.

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46 FOOD WEB A diagram that defines ALL OF THE POSSIBLE FOOD CHAINS in an ecosystem. Ex:

47 PYRAMID OF ENERGY A diagram that defines the passage of ENERGY though a food chain. Energy is measured in Joules, symbol J. PRODUCERS always have the most energy (bottom of pyramid). TOP CARNIVORES always have the least energy (top of pyramid). About 10 % of the total energy is passed on from one trophic level to the next. That is, 90% is lost due to processes such as:

48 PYRAMID OF ENERGY... Example: Corn (10000 J) Mouse (1000 J) Snake (100 J) Hawk 10 J

49 A PYRAMID OF BIOMASS is a graphical representation of the TOTAL BIOMASS of all the members of each trophic level. Often similar in shape to a Pyramid of Energy.

50 POPULATION Describes members of the SAME SPECIES living in the same ecosystem or habitat Examples: Caribou population in Labrador Hedgehog population in New Brunswick

51 COMMUNITY Describes ALL POPULATIONS of the variety of species in the same ecosystem or habitat. Examples: Newfoundland & Labrador Community

52 BIODIVERSITY: The variety of life. Why is biodiversity important to an ecosystem? The higher the level of biodiversity, the more STABLE that ecosystem is in the long-term.

53 Species a group of closely related organisms that are able to breed with one another

54 Carrying Capacity See Page. 30 The carrying capacity of an ecosystem is the number of individual species that can survive in an area over time. If something limits the size of a population, it is known as a limiting factor. 1. Availability of Raw material 2. Availability of Energy 3. Accumulation of waste products and their means of disposal 4. interactions among living organisms

55 Water Cycle

56 Carbon-Oxygen Cycle

57 Nitrogen Cycle

58 Precautionary Principle a moral, legal and political ideas which states : if an idea or policy might cause harm to the public or the environment, it is the responsibility of those pushing the idea or policy to prove that it will not cause harm, unless there s a lot of scientific evidence to suggest its ok. In other words, caution ahead of time, BEFORE we make decisions or take action. That s completely opposite of the old development ethic. It applies to individuals, businesses, and Governments.

59 Developing and using our resources has the potential to bring great prosperity, but that shouldn t degrade the quality of our environment. WE NEED TO BE STEWARDS TO OUR ENVIRONMENT AND BECOME A BETTER ECOCITIZEN reduce your carbon footprint!!! Examples:

60 Our NL Government must lead with sustainable examples, and decide how our resources are to be used. As a Province, we also work towards environmental goals set by national and international agreements or programs. A Government s role is to protect our future, provide leadership, help make us better global citizens. That includes municipal Governments as well as our Provincial Government. The decisions and programs coming to or from them help us do that. Ex. Passing and enforcing environmental protection Giving money to projects and organizations aiming to help improve the environment Participating in global agreements Industry s role is to comply with regulations and be a good community citizen ( supporting projects, hiring / buying locally ). Setting examples of sustainable resource use and concern for the environment. Your role as an individual is called eco-citizenship. Being active in helping maintain a high quality environment through your decisions and actions. How? By doing a course like this, you gain knowledge to help you make better informed decisions about issues and be aware of who s doing their part and who isn t. Build an attitude of awareness and concern. Practice doing things in a more environmentally friendly way. (For lots of examples, browse through pages 47-54)

61 (Earth as a Spaceship analogy...understand that Earth is a closed system ) a closed system is a physical system which doesn't exchange any matter with its surroundings, and isn't subject to any force whose source is external to the system a region that is isolated from its surroundi ngs by a boundary that admits no transfer of matter or energy across it.

62 The biosphere is the portion of earth where life is found, and can be subdivided into three parts: geosphere (lithosphere) - the solid portion of the earth...rock, hills, soils and the resources contained there atmosphere - hydrosphere - the gas portion of the planet that protects, insulates the water portion of earth...all freshwater and marine environments as well as groundwater and glaciers Lithosphere divided into eco-regions based on areas of distinct natural communities Labrador West is in the New Quebec-Central Plateau Eco-Region